Conveyors are mechanical devices that typically include a plurality of rollers (e.g., cylindrical or spherical rollers) that carry and transfer items over some distance or travel path. In some examples, the travel path across an upper conveying surface of the conveyor can be horizontal or at an incline (positive or negative slope). In some examples, the conveying surface is a powered belt for moving or transferring the items over some distance. In yet other cases, the conveying surface of some conveyors have powered rollers for moving the items, but other examples, the rollers are passive, free spinning rollers, where the items being transferred move along the travel path by gravity. In some cases, a moving belt overlays the rollers to help support the items on the conveyor. Conveyors are used in a wide variety of material handling applications such as for moving boxes, parcels, luggage, parts and other items.